1. Field of the Invention
The present invention relates generally to a method and apparatus for making an electrical harness of the type including a connector having a housing with insulation displacement type contacts loaded therein, each contact connected to an insulation clad wire.
2. Brief Description of the Prior Art
More and more, manufacturers of electronic products are relying on electrical harnesses employing insulation displacement type contacts to eliminate some of the inefficiencies and costs associated with other types of electrical connections. A typical electrical harness of the type that is gaining wide acceptance is one which generally comprises a connector having a housing with insulation displacement type contacts loaded therein. Each contact is connected to an insulation clad wire. The wires are generally of different lengths with different segments of insulation removed from the wire ends opposite the connector.
Because of the desirability of eliminating labor costs, automatic equipment is now being employed to produce electrical harnesses of the type described. One example of such a machine is disclosed in U.S. Pat. No. 4,136,440 which was granted on Jan. 30, 1979.
Generally, said U.S. Pat. No. 4,136,440 discloses a method and apparatus of making an electrical harness of the type described which:
positions a connector at a first station, PA1 simultaneously feeds first ends of a plurality of wires uniformly past a second station to the first station, PA1 inserts the wires into the connector at the first station, PA1 forms loops of differential lengths in the wires between the first and second stations, PA1 presses the wires into channels adjacent the second station having cutting blades therein for severing the insulation on the wires, PA1 gripping the wires adjacent to second station, PA1 shearing the wires at the second station, and PA1 imparting an axial force on the wires to draw the wires past the cutting blades and strip the wire insulation therefrom. PA1 (a) positioning a connector on a first station; PA1 (b) holding at least a number of wires corresponding to the number of contacts at a second station remote from said first station; PA1 (c) moving said connector to said second station so that each contact is in alignment with each held wire; PA1 (d) simultaneously inserting each held wire into its corresponding contact at the second station; PA1 (e) moving said connector back to said first station and simultaneously drawing a predetermined length of wire defined between said connector and said second station; and PA1 (f) cutting all the held wires at the second station. PA1 said wire looping members being mounted relative to one another so that said wire engaging ends initially engage each respective wire at different distances from the connector. PA1 a connector feed station adjacent to said first station whereat a second connector is positioned prior to being positioned at the first station; a load and eject assembly associated between said connector feed station and said first station including a reciprocally mounted connector engaging push member having one portion thereof engaging the second connector at the connector feed station and having another portion thereof engaging the first connector of a completed electrical harness at the first station, said connector engaging push member being actuable to move in a direction from the connector feed station toward the first station so that the second connector at the connector feed station is moved to the first station while, at the same time, the completed electrical harness is ejected from the opposite end thereof; and control means for actuating said load and eject assembly after a completed electrical harness is presented to the first station.
In addition said U.S. Pat. No. 4,136,400 discloses a looping assembly for forming loops of differential lengths in the wires wherein the wires are axially engaged by the looping assembly at points on the wires that are in the same plane perpendicular to the plane of the wires and, therefore, are at the same distance from either one of the two stations. This may be satisfactory for electrical harnesses having relatively wide center spacing between the contacts and wires, e.g., 0.156 inches. However, when attempting to manufacture electrical harnesses having contact center distances such as 0.100 inch or less, the thicknesses of the wire engaging members become a limiting factor when they are in the same plane.
In addition, a relatively sophisticated means of positively driving and feeding the wire is required in U.S. Pat. No. 4,136,440. The wires must be power dereeled between said second and first stations and be driven by suitable wire feeding means.
Further, it is desirable to have an automatic connector loading and electrical harness ejecting means which is not provided for in U.S. Pat. No. 4,136,440. Instead, the connectors are manually loaded to the first station.